The Guidelines state that they "particularly do not address the encoding of physical description of textual witnesses: the materials of the carrier, the medium of the inscribing instrument, the layout of the inscription upon the material, the organisation of the carrier materials themselves (as quiring, collation, etc.), authorial instructions or scribal markup, etc." (p. 557). On the other hand, the Guidelines expressly recommend that a reference system for each encoded text without a "pre-existing associated reference system" specify "at least the page boundaries of the source text" (p. 184). Yet page-boundaries belong to a bibliographical structure that starts with the line and proceeds through the page and the forme, to end in the gathering or quire. Despite its own principles, TEI relies on one part of the bibliographical structure.
TEI does not represent the special relationships holding among bibliographical elements. For this reason the TEI fw ("forme-work") tag, which handles many of these features of physical books, falls within front, body, and back tags rather than subsuming them. As well, TEI sometimes treats sections of a text belonging to the printer or publisher as if they belonged to the author. The title-page contains the name and address of those responsible for the making of the book into formes, which are revealed in the signatures. It labels the physical book, not necessarily the text (which generally has a separate heading). The table of contents correlates logical structure with widely separated page numbers, which are purely a reflection of the makeup of the physical book. The errata page cannot be read as text. It is a list of instructions: bibliographical coordinates (page and line numbers, often) matched with changes in text, corresponding to a computer batch list of search-and-replace commands. As such, errata pages are bibliographical. They belong to the printer, who is the maker of the primary bibliographical material. TEI guidelines do not yet handle the joint responsibility of the printer/scribe and the author for a book or manuscript.
As a result, RET texts do not use the TEI Document-Type Definition. RET structures are different from those identified by TEI.